Our major laboratory focus on the study of the molecular biology and latency of varicella-zoster virus (VZV) has continued. We are performing finer endonuclease mapping of varicella zoster virus DNA strains as well as completing a preliminary map of 58 viral encoded transcripts. We are using our extensive library of VZV DNA recombinants to map various VZV encoded gene products. Using marker rescue techniques we are attempting to map the genetic loci associated with VZV resistance to antiviral drugs. By hybrid selection and in vitro translation of viral RNAs and immunoprecipitation with polyclonal and monoclonal antibodies we are identifying and mapping major viral proteins. By transformation of thymidine kinase deficient mouse L cells we have identified and mapped the gene responsible for the VZV pyrimidine kinase enzyme. During the coming year we plan to initiate in situ hybridization studies of human tissues for latent VZV DNA and RNA sequences.